Refrigerator door construction



Aug. 19, 1952 r R. SAUNDERS 2,607,086

. REFRIGERATOR DOOR CONSTRUCT LON a Filed June 23, 1948 Patented Aug.19, 1952 Application t'll Illa 23, 1948, Serial Nafaaszci n1 GreatBritain July 11, 1947 1 5 Claims. (o1. zit-35) This invention relates tothermally insulated chambers such as refrigerators, cold storagechambers and the like. It is, of course, well known that, in the case ofdomestic and other refrigerators, cold storage chambers and the like,there is a considerable temperature difference on opposite sides of thedoor, which temperature difference may be 70 or even more, particularlywhere thedeep freezing process is in. use. Here'- tofore the jointaround the door has been made by means of one or-more rubber or likegaskets which are pressed into contact with the door frame and with anot inconsiderable pressure. With refrigerators, cold storage chambersand the like as previously constructed, trouble has beenexperienced'from the fact that when the door is opened moisturecondenses around the door frame, which moisture, after the door isclosed. turns to ice with; theresult that the gasket or gaskets is orare frozen to the door frame. Considerable force will then be necessaryto open the door which is often damaged or distorted in the process. Thechief object of the present invention is to overcome this disadvantage.

According to the main feature of the present invention, the door whenclosed is adapted to define a closed chamber or peripherally extendingspace around its edge between the inside and outside of therefrigerator, cold storage chamber or the like, and means are providedfor maintaining said chamber at a temperature above freezing point.

Conveniently the. door, when. closed, is, adapted to form two suchchambers between its edge and the door frame.

According to another feature of the present invention, the use of rubberor like gaskets is dispensed with and a metal to metal joint is employedbetween the door and the door frame. In this case, and particularlywhere the frame of the door and the door frame are in the form of metalcastings, it is desirable to use a metal of low thermal conductivitysuch as magnesium or a magnesium alloy. Also where the frame of the doorand the door frame are metal castings, it is necessary to make theframes in two parts which are heat-insulated from one another in orderto prevent the conduction of heat from the insulated Figure 1 isafrontele'valtion of :door and. framing" tte 'the present invention,

Figure 2 is asecti'on unlined- 1131 "lii'gure 1 and V a Figure sis asectionon Mei- 4 of Figure 1. Referring now to the accompanyingdrawings, inthe embodiment of the present invention therein illustratedthe doorirame: t0 and the framing ll of the door itself aramaeesame formof castings of a metal of low thermalconductivity, such as magnetiumor amagnesium alloy. The door l0 itself 'is lagged "with cork or'othersuitable material in any desired manner as at l2, this forming no partof' thepresent invention and the chamber'i's sinularly laggedysee I3. Itfollows thatas theidoor frame "1- and' the framing H of the dooriaerraramaeeer metal or other thermally conductive material, some meansmust be provided rroe reveaung-tne-eonduction or heat fromtheoutside-"to the inside of the. refrigerator, cold storage chamber orthe like, and with this obj'ect in view thedoor frame HI and the framingl-I': ofthe door are each made in two parts, a front: or exterior partwith rear or exterior party-fies shown in Figures 2: and 3) anda stripof heat insulating material it, such for example rubber or the materialsold. under the trade-mark Tufnol, or other resilient thermallyinsulating material is inserted between the two parts, which are, ofcourse, suitably held together to form the complete frames.

The framing H of the'door is. substantially semi-circular incross-section and the door framing I 0 may also be regarded as being ofcircular shape in cross-section as will be seen from the drawings. Thedoor frame l0, however, is provided around its front with a bead l5which may be substantially circular in cross-section and the framing I Iof the door is provided at the rear with an annular bead IS. The partsare so proportioned that with the door closed the bead l 5 on the doorframe In contacts with the framing I l of the door and, also, the backof the door frame Ill contacts with the bead l 6 on the framing H of thedoor. In addition to the front and back contacts between the door frameand the framing of the door, the two heat insulating strips M in theframes likewise contact each other (see Figures 2 and 3). The door whenclosed thus serves to define two closed chambers or spaces l1 and I8which extend peripherally all around its edge. By making the frames of ametal or allow or other thermally conductive material such as thatreferred to above it is easy to secure air-tight joints where the partsare in direct contact without the use of high pressures such as arenecessary when rubber or like gaskets and wooden frames are used.Furthermore, the strength of the metal frames is such that there will beno tendency of the same to distort so that air-tight joints will alwaysbe maintained. H A I I a Now it will be appreciatedtliatwith metal tometal joints such as those described above the tendency of the joint tofreeze up due to the condensation of moisture when the door is opened isconsiderably enhanced. In order to avoid all possibility of the doorfreezing up, means are provided for heating the air within the closedchambers defined by the door when closed to a temperature above freezingpoint. means may be employed for heating the air with in the closedchambers without departing from the scope of the present invention. Forexample, low temperature electrical heaters l9 may be'employed and theymay be thermostatically cona claim 1 inwhich the interiorly andexteriorly dis- Any' suitable Yposed portions of the said door frame andsaid trolled. The air within the two closedchambers l1 and 18 may beheated to the same temperature or to diflerent temperatures as desired.

Means may be provided for draining. away any moisture which condenses inthe closed chambers. z v

The circular bead l5 all around-the edge ofthe front of the door servesvnot only to provide one oi. the joints between the door frame; and theframing for the door but, also serves as aconvenient means of hinging"the door (see 20) and carrying the fastening means (not shown).

Ifdesired, the'door; when, closed; ,may be adapted to define onlyasingle closed-chamber, or more than two closed chambers around its edgewithout departing from the scope of the present invention. 1 Y I Also,whilstit is preferred to. make the frames of metal andito dispensewith-the use of gaskets. the feature .of the present invention l wherebythe door when closed :defines oneor more closed chambers around its.edge, which chamber or chambers is or are heated to a, temperature abovefreezing point, may also .be usefully applied to wooden, plastic orother doors with the joints formed of rubber orlike gaskets'or, in somecases,

without gaskets.

I claim: I

l. A thermally insulated chamber ofthe class described, said chamberhaving an opening therein, comprising: a-door frame of thermallyconductive material mounted in said-opening'and 4 comprising interiorlyand exteriorly disposed portions thermally insulated from each other; adoor comprising a framing of thermally conductive material hingedlymounted in said door frame, said framing comprising interiorly andexteriorly disposed portions thermally insulated from each other, saiddoor frame and said framing of said door being shaped for direct contacttherebetween at the interior and exterior portions thereof and defininga peripherally extending space therebetween when the door is closed; anda heater disposed in said peripheral space, for maintaining thetemperature in said space above the freezing point.

2. A thermally insulated chamber according to framing of said door arethermally insulated from one another at the peripheral portions thereofeach by a strip of resilient thermally insulating material, thearrangement being such that when the door is closed said strips engageeach other dividing said peripheral space intotwo portions interiorlyandexteriorly disposed with respect to each other. i

3. A thermally insulated chamber'according to claim 2 wherein saidheater comprises at least one low. temperature electrical heaterdisposed in one of said portions of said peripheral space.

4. A thermally insulated chamber according to claim 3 wherein the twoportions of said peripheral space are heated to different temperatures.

5. A thermally insulated chamber according to claim 3 wherein said lowtemperature electrical heater is thermostatically controlled.

RALPH SAUNDERS.

REFERENCES CITED The following references are of record in the file ofthis patent: a

UNITED STATES PATENTS

